<template>
  <div class="app-container">
    <!--查询表单-->
    <el-form :inline="true" class="demo-form-inline">
      <!-- 所属分类：级联下拉列表 -->
      <!-- 一级分类 -->
      <el-form-item label="课程类别">
        <el-select
          v-model="searchObj.subjectParentId"
          placeholder="请选择"
          @change="subjectLevelOneChanged"
        >
          <el-option
            v-for="subject in subjectNestedList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"
          />
        </el-select>

        <!-- 二级分类 -->
        <el-select v-model="searchObj.subjectId" placeholder="请选择">
          <el-option
            v-for="subject in subSubjectList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"
          />
        </el-select>
      </el-form-item>

      <!-- 标题 -->
      <el-form-item>
        <el-input v-model="searchObj.title" placeholder="课程标题" />
      </el-form-item>
      <!-- 讲师 -->
      <el-form-item>
        <el-select v-model="searchObj.teacherId" placeholder="请选择讲师">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"
          />
        </el-select>
      </el-form-item>

      <el-button type="primary" icon="el-icon-search" @click="getPageList()">查询</el-button>
      <el-button type="default" @click="resetData()">清空</el-button>
    </el-form>

    <!-- 表格 -->
    <el-table
      v-loading="listLoading"
      :data="list"
      element-loading-text="数据加载中"
      border
      fit
      highlight-current-row
      row-class-name="myClassList"
    >
      <el-table-column label="序号" width="70" align="center">
        <template slot-scope="scope">{{ (page - 1) * limit + scope.$index + 1 }}</template>
      </el-table-column>

      <el-table-column label="课程信息" width="470" align="center">
        <template slot-scope="scope">
          <div class="info">
            <div class="pic">
              <img :src="scope.row.cover" alt="scope.row.title" width="150px" >
            </div>
            <div class="title">
              <a href>{{ scope.row.title }}</a>
              <p>{{ scope.row.lessonNum }}课时</p>
            </div>
          </div>
        </template>
      </el-table-column>

      <el-table-column label="创建时间" align="center">
        <template slot-scope="scope">{{ scope.row.gmtCreate.substr(0, 10) }}</template>
      </el-table-column>
      <el-table-column label="发布时间" align="center">
        <template slot-scope="scope">{{ scope.row.gmtModified.substr(0, 10) }}</template>
      </el-table-column>
      <el-table-column label="价格" width="100" align="center">
        <template slot-scope="scope">
          {{ Number(scope.row.price) === 0 ? '免费' :
          '¥' + scope.row.price.toFixed(2) }}
        </template>
      </el-table-column>
      <el-table-column prop="buyCount" label="付费学员" width="100" align="center">
        <template slot-scope="scope">{{ scope.row.buyCount }}人</template>
      </el-table-column>

      <el-table-column prop="status" label="课程状态" width="100" align="center">
        <template slot-scope="scope">
          <el-tag
            :type="scope.row.status === 'Draft' ? 'primary' : 'success'"
          >{{ scope.row.status === 'Draft' ? '未发布' : '已发布' }}</el-tag>
        </template>
      </el-table-column>

      <el-table-column label="操作" width="150" align="center">
        <template slot-scope="scope">
          <router-link :to="'/course/info/'+scope.row.id">
            <el-button type="text" size="mini" icon="el-icon-edit">编辑课程信息</el-button>
          </router-link>
          <router-link :to="'/course/chapter/'+scope.row.id">
            <el-button type="text" size="mini" icon="el-icon-edit">编辑课程大纲</el-button>
          </router-link>
          <el-button
            type="text"
            size="mini"
            icon="el-icon-delete"
            @click="removeById(scope.row.id)"
          >删除</el-button>
        </template>
      </el-table-column>
    </el-table>

    <!-- 分页 -->
    <el-pagination
      :current-page="page"
      :page-size="limit"
      :total="total"
      style="padding: 30px 0; text-align: center;"
      layout="total, prev, pager, next, jumper"
      @current-change="getPageList"
    />
  </div>
</template>
<script>
import course from '@/api/edu/course'
import teacher from '@/api/edu/teacher'
import subject from '@/api/edu/subject'

export default {
  data() {
    return {
      listLoading: true, // 是否显示loading信息
      list: null, // 数据列表
      total: 0, // 总记录数
      page: 1, // 页码
      limit: 10, // 每页记录数
      searchObj: {
        subjectParentId: '',
        subjectId: '',
        title: '',
        teacherId: ''
      }, // 查询条件
      teacherList: [], // 讲师列表
      subjectNestedList: [], // 一级分类列表
      subSubjectList: [] // 二级分类列表,
    }
  },
  created() {
    // 1. 获取数据结构
    this.getPageList()
    // 2. 课程分类数据(搜索)
    this.initSubjectList()

    // 3. 讲师列表数据
    this.initTeacherList()
  },
  methods: {
    getPageList(page = 1) {
      this.page = page
      course
        .getPageList(this.page, this.limit, this.searchObj)
        .then((response) => {
          this.list = response.data.rows
          this.total = response.data.total
          this.listLoading = false
        })
    },
    // 初始化 课程分类列表
    initSubjectList() {
      subject.getNestedTreeList().then((response) => {
        this.subjectNestedList = response.data.subjectList
      })
    },
    initTeacherList() {
      teacher.getList().then((response) => {
        this.teacherList = response.data.items
      })
    },
    subjectLevelOneChanged(value) {
      for (var i = 0; i < this.subjectNestedList.length; i++) {
        if (this.subjectNestedList[i].id == value) {
          this.subSubjectList = this.subjectNestedList[i].children
          this.searchObj.subjectId = ''
        }
      }
    },
    // 清空
    resetData() {
      (this.searchObj = {
        subjectParentId: '',
        subjectId: '',
        title: '',
        teacherId: ''
      }),
      (this.subjectList = []) // 二级分类
      this.getPageList()
    },
    removeById(id) {
      // debugger
      this.$confirm(
        '此操作将永久删除该课程，以及该课程下的章节和视频，是否继续?',
        '提示',
        {
          confirmButtonText: '确定',
          cancelButtonText: '取消',
          type: 'warning'
        }
      )
        .then((response) => {
          return course.removeById(id)
        })
        .then(() => {
          this.getPageList()
          this.$message({
            type: 'success',
            message: '删除成功！'
          })
        })
        .catch((response) => {
          if (response === 'cancel') {
            this.$message({
              type: 'info',
              message: '已取消删除'
            })
          } else {
            this.$message({
              type: 'error',
              message: '删除失败！'
            })
          }
        })
    }
  }
}
</script>
<style scoped>
.myClassList .info {
  width: 450px;
  overflow: hidden;
}
.myClassList .info .pic {
  width: 150px;
  height: 90px;
  overflow: hidden;
  float: left;
}
.myClassList .info .pic a {
  display: block;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
}
.myClassList .info .pic img {
  display: block;
  width: 100%;
}
.myClassList td .info .title {
  width: 280px;
  float: right;
  height: 90px;
}
.myClassList td .info .title a {
  display: block;
  height: 48px;
  line-height: 24px;
  overflow: hidden;
  color: #00baf2;
  margin-bottom: 12px;
}
.myClassList td .info .title p {
  line-height: 20px;
  margin-top: 5px;
  color: #818181;
}
</style>
